Apparatus for extracting water from paper stock



J. MAZER Aug. 9, 1955 APPARATUS FOR EXTRACTING WATER FROM PAPER STOCKFiled Feb. 28, 1951 INVENTOR f /C05 MAZEQ TTOR VE) United States PatentAPPARATUS FOR EXTRACTING WATER FROM PAPER STOCK Jacob Mazer, RockvilleCentre, N. Y.

Application FebruaryZS, 1951, Serial No. 213,119

14 Claims. (Cl. 92 -51) This invention relates to paper manufacture and,more particularly, to an improved method of, and apparatus for,morerapidly and more efficiently extracting water from the stock carriedon the wire in the form of a pulp web.

Inpaper making machines presently in use, once the stock is deposited onthe wire as a pulp web of high water content, successive water removalor drying steps are applied, in addition to the normal water drainagethrough the wire as the pulp web progresses through the machine. In onetype thereof, suction is applied as the wire carrying the pulp webpasses a series of spaced fiat suction boxes, and this is followed bysuccessive mechanical or squeeze pressures applied at the couch roll andthereafter, the press roll series. In another type thereof, suction isapplied as the wire carrying the pulpweb passes a series of spaced flatsuction boxes, and this is followed by the further application ofsuction atthe suction box I in an extractor drum or suction couch, afterwhich mechanical pressure is applied at the press roll series.

The invention method and apparatus herein involved are directed toimprovements in the application of suction applied to the pulp Web onthe wire as it passes the suction boxes, so that a greater amount ofwater may be extracted from the pulp at the respective suction boxes,whether fiat or in a roller drum.

In the present type of rotary extractor drum or suction 1 couch, knownto the trade as the Millspaugh type, the

shell of the drum or couch over which the 0 wire carrying thelpulpawebpasses, is perforated, and suction mechanically developed by externalpumps is applied to: the stock in the pulp web through a suction boxrigidly mounted against rotation within the drum or couch, the suction.

box being essentially of the confonnation of a trough,

the sidewalls of which are in sealing engagementwiththe interior and endwalls of the shell of the drum. orcouchw to subtend an arc area definingan arcuate zoneof up.-

aforementioned may vary from 2% to dependent upon the variable factors.above mentioned, but with medium Weight stock and the standard externalsuction pump above referred to, is about 5%, i. e. the stock at theentry of the pulp web'to the suction zone is about bone dry and at theexit thereof fromthe suction zone isabout bone dry.

In the present type offlat suction box arrangement at the wet end of thepaper making machine, thehorizontal planar surface of the box over whichthe wire carrying thepulp webpasses, is perforated and suction mechani-2,714,839 Patented Aug. 9, 1955 "ice cally developed by external suctionpumps is applied to the stock passing thereover, the amount of vacuumdeveloped in the suction box being on the order of 8" to 16" Hg,dependent upon the thickness of the sheet, the

freeness of the fibres and the size of the suction pump used, and theamount of extraction of water from the stock in the pulp web passingover the area defining the planar. suction zone aforementioned beingrelatively small for each such box for medium weight stock and thestandard external pump used in the industry, a plurality of such suctionboxes being arranged in spaced series so that the pulp web by the timeit passes the last of the suction boxes is usually about 15% bone dry.

The action at the suction box, whether in the drum or roll or in thespaced flat type, involves a drawing in of air through the pulp web andthe perforations on the surface of the box over which the wire passes,with the result that a mixture of air, water and Water and entrained airis drawn into the suction line.

While various attempts have been made to increase the amount of waterextracted from the stock by the suction boxes, whether in the suctioncouch roll or an extractor drum of the character aforesaid, or of thefiat type, the same have not been successful because of the high cost ofmechanical equipment and power for developing the higher degree ofvacuum requisite for such purpose.

In accordance with the present invention, the water extraction from the.stock at the suction couch roll or extractor drum. and/or the flatsuction boxes, is very substantially increased in an. inexpensive mannerand without requiring any increase of the amount or size of themechanical equipment or power consumption, the method and apparatus ofthe invention being applied to a standard suction couch roll orextractor drum and/ or a standard flat suction box modified ashereinafter outlined.

In accordance with the present invention, steam is discharged on thestock in the form of the pulp Web carried on the wire in a substantiallyenclosed area along a zone directly above the subtended perforated arcarea of the suction box mounted in the extractor drum or couch rolland/or the perforated horizontal planar surface area of the flat suctionboxes over which the pulp Web passes,

so that as the steam impinges against the surface and penetratesthroughthe interstices of the pulp web in the aforesaid zone thereof,the same is drawn through the perforations and into the suction box bythe vacuum maintained therein by the pumps. Such steam, in its movement,upon contact with the pulp web, raises the temperature of the water inthe pulp web through heat exchange, whereby a small part of the steamcondenses and the remaining steam, as it passes through the pulp web, ismixed and entrained with the water thereof, so that as both water andsteam pass into the suction box under the influence of the mechanicalsuction, further condensation of the steam takes place, with the resultthat a vacuum, which is independent of, and additive to, the mechanical.suction of the pumps, is developed in the suction box.

By virtue of the condensation of steam aforesaid, there is establishedwithin the suction box a degree of vacuum considerably greater than thatdeveloped by the external.

mechanical pumps and, consequently, since this is translated into agreater suction effect upon the stock of the pulpweb at the suction zonein the subtended arc area or planar surface aforesaid, a greaterextraction of water is attained.

Ina further embodiment of this invention, instead of relying solely uponthe extracted Water from the pulp webmixed and entrained with thedischarged steam in the suction zone as the mediumfor condensing thesteam and thereby increasing the vacuum in the suction box, thisinvention contemplates the provision within the suction box of a coolingspray of water which, acting on the steam mixed and entrained with thewater as it enters into the suction box, serves to condense the steam inthe manner of a jet condenser. In this embodiment, a vacuum in excess of20" Hg may be attained within the suction box and consequently, theamount of extraction of water from the stock in the pulp web may begreatly increased.

Wherever the expression paper is herein applied, it is to be understoodthat the Same includes pulp, board or other fibrous material in the formof aweb of stock carried on a wire and subjected to Water extraction.

For an understanding of the invention principles, reference is made tothe following description of typical embodiments thereof illustratedschematically in the accompanying drawing, in which:

Fig. 1 is a partial diametric sectional view of an extractor drum in theform of a suction couch roll arrangement, embodying the structure andillustrating the method of the invention; and

Fig. 2 is a partial diametric sectional view of a flat suction boxarrangement, embodying the structure and illustrating the method of theinvention.

Referring to the drawing, and particularly to Fig. l, the Wire comingfrom the apron or forming roll (not shown), as the case may he, carriesa web of paper stock over a longitudinally spaced series of suctionboxes (not shown in this embodiment) and in its movement in thedirection of the arrow from the right of the drawing, is trained overthe rotating extractor drum or suction couch roll 20.

The suction couch roll has formed along the surface of its cylindricalshell 21 a series of perforations 22, which perforations may be inangular spaced relation so as to provide a zig-zag formation, saidperforations being spaced sufficiently close to each other so that theperipheral surface thereof is substantially reticulated. The pulp web 15of stock entering from the right of the drum or roll 20 is approximately15% bone dry as a result of drainage through the wire and the action ofthe suction boxes in advance of said drum or roll 20.

The rotating extractor drum or suction couch roll 20 has mountedinteriorly of the shell thereof, for maintenance in fixed angular andnon-movable relation thereto, a suction box 25 of trough-shapeconfiguration, the sidewalls 26, 26 defining the walls extending axiallyof the drum or roll 20 to subtend an arcuate area or zone 23 hereinaftercalled the suction zone of the couch roll. The edges of the sidewalls26, 26 and the end walls (not shown) of the suction box 25 mount packingmembers 27, which engage the inner face of the shell 21 to form asubstantially airtight seal therewith, the packing mem bers 27 beingfirmly held against the shell for defining the suction zone 23, by theaction of springs 28, which press against the bottom wall 29 of suctionbox 25.

An external vacuum pump unit (not shown) is connected in the usualmanner to the interior of suction box 25 and in connection with theformation of medium weight stock, develops and maintains within thesuction box a vacuum in the range of about 12" Hg, as a result of whichthe stock of the pulp web 15 carried on the wire as it passes thefurthermost or left edge of the suction zone 23, is about 20% bone dry.

The structure of the apparatus described to this point is that of theknown prior art, and the structure from this point on to be describedinvolves the apparatus which, when applied in accordance with the novelmethod of the invention, produces the increased extraction of water fromthe pulp web at the extractor drum or suction couch roll.

In accordance with the present invention, there is mounted above theextractor drum or suction couch roll 29, and axially of the suction box25, a steam discharge unit which comprises a steam pipe 30, havingarcuate deflector shields 31, which may be welded to or formed integralwith said steam pipe, said steam pipe and deflector shields being oflength co-extensive with that of the extractor drum or couch roll. Thefree edges of the deflector shields extend to encompass or supertend asteam arc area or zone 24, slightly less in width than the arcuate areaor suction zone 23 subtended by the suction box 25, the aforesaid freeedges extending radially a slight distance from the upper surface of thepulp web 15, and laterally the distance of one perforation from theedges of the subtended suction zone, so that an air seal is formedbetween the inner edges of the packing members 27 of the suction box 25and the outer edges of the deflector shields 31, whereby air drawn intothe suction box at the outer edges of the deflector shields and passingbetween the free edges thereof and the pulp web, prevents the escapeinto the atmosphere of steam discharged from the steam pipe 36, andeffectively provides a steam chest discharging only into the supertendedsteam zone. The steam pipe 30 has formed therealong two series of spacedangularly directed discharge apertures 33, 33, so that steam issuingtherefrom is angularly directed against the inner surfaces of deflectorshields 31 and as so defiected, impinges in relatively evenlydistributed volume along the entire surface of the pulp web 15, passingthrough the steam zone" 24, the representative angular movement of thesteam being indicated by lines 34.

Within suction box 25 and extending axially of the extractor drum orroll 20, there is provided a water discharge pipe 35 having twoangularly disposed series of spaced orifices 36, the orifices being inthe form of perforations defining a spray nozzle through which waterfrom the cold Water supply line may be discharged as a spray 37preferably (although not necessarily) upwardly and radially toward thesidewalls 26, 26' of the suction box 25 for deflection. The waterdischarge pipe 35 is preferably (although not necessarily) mountedwithin and extending axially of vacuum pump conduit 38 leading from anend of the suction box to the vacuum pump.

In one embodiment of the invention, the steam discharge assembly aloneis applied in connection with the suction box 25 of the extractor drumor couch roll 20, while in the other embodiment of the invention thereis additionally applied the cold water spray 37.

Referring particularly to Fig. 2, wherein is illustrated a flat suctionbox being one of a spaced series disposed in advance of the extractordrum or couch roll and in connection with which like numbers are appliedto elements identical with those disclosed in the embodiment of Fig. 1,the wire 15 coming from the apron or forming roll (not shown), as thecase may he, carries, in the direction of the arrow, a web 15 of paperstock over the planar top surface 21 of suction box 25.

The suction box is of a standard rectangular type, the top surface ofwhich has perforations 22, which are preferably in zig-zag formation,such top surface 21 being made of wood or metal as the case may be, andbeing fixedly mounted on and to the sidewalls 26, 26' forming the troughof the suction box, as by bolting and joint sealing. Directly above theplanar surface 21 aforesaid of the suction box, there is disposedaxially thereof a steam discharge unit which comprises a steam pipe 30having arcuate deflector shields 31, which may be welded to or formedintegral with said steam pipe, the length of the steam pipe anddeflector shields being of a length co-extensive with that of the planarsurface of the suction box, and the free edges of the deflector shieldsextending to encompass or supertend a steam area or zone 24 slightlyless in width than the subtended area 23 of the planar surface subtendedby the walls of the suction box, the aforesaid free edges of thedeflector shields extending a slight distance from the upper surface ofthe pulp web 15 and laterally the distance of one perforation from theedges of the subtended area I 23, so that an air seal is formed betweenthe trough walls of the suction box and the outer edges of the deflectorshields, whereby air drawn in by the suction box at the outer edges ofthe deflector shields and passing between.

the free edges thereof and the pulp web, prevents the escape into theatmosphere of steam discharged fromthe steam pipe and effectivelyprovides a steam chest discharging only into the supertended steam zone.

Within the suction box 25 and extending axially thereof there isprovided a water discharge pipe 35 having two angularly disposed seriesof spaced orifices 36, the orifices being in the form of perforationsdefining a spray nozzle through which water from the cold water supplyline may be discharged as a spray, preferably (although not necessarily)upwardly and radially toward the sidewalls 26, 26 of the suction box 25'for deflection, said water discharge pipe being preferably (although notnecessarily) mounted within and extending axially of the vacuum pumpconduit 38 leading from one end of the suction box 25 to the vacuum box.

In operation, in accordance with the first embodiment of this inventionillustrated in Fig. l, as steam is discharged from steam pipe 30 intothe steam zone 24, the saturated steam, upon contacting with the pulpWeb 15, heats up the water therein through heat exchange (with resultantcondensation of part of the steam) and, under the influence of themechanical suction at the suction box 25, effective at the suction zone23,.the steam passes through the interstices of the pulp Web 15 and asmixed, and while entrained with the water of the pulp web, is drawnthrough the perforations of the shell into the trough of the suctionbox; the steam, during such passage, becoming condensed as it movestoward the outlet of the suction box, such condensation causing thedevelopment of a vacuum in the suction box, independent of themechanical vacuum maintained by the external pump aforesaid and additivethereto, whereby as a result of such increased vacuum in the suctionbox, a greater amount of water extraction of the pulp web passing thesuction zone is eifectuated. In accordance with this embodiment, thesuction, as additively increased, may in connection with medium weightstock, attain a value of approximately 15" to 16 Hg, and the amount ofextraction of water is increased, so that at the leaving end of thecouch roll, pulp of this character may be from 23% to 25% bone dry.

In accordance with the second embodiment of this invention illustratedin Fig. 1, involving the utilization of the cold water spray 37 withinthe suction box 25, the steam discharged into the supertended arcdefining steam zone 24 performs in the same manner as that outlined inconnection with the first embodiment, except that by virtue of theutilization of the cold water spray, the steam entering into the suctionbox, mixed and entrained with Water, is subjected to a more rapid andmore complete condensing effect in the nature of a jet condenser effect,with the result that a much higher vacuum is attained within the suctionbox and a much greater extraction of water from the pulp web iselfectuated. The vacuum developed in accordance with this secondembodiment is in excess of 20 Hg, the only limitation on the approach ofthe vacuum to be developed in the suction box 25 being that involvingthe necessity of preventing resistance to the movement of the paper pulpon the wire, the amount of water extraction developed at the vacuumwithin the range of 20 Hg being from 25% to 28% bone dry.

No detailed description of operation is given with respect to theembodiments of this invention illustrated in Fig. 2 and involving theflat suction boxes, since the operative association of the elements andtheir functions are identical with those outlined in relation to theembodiments of Fig. 1.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principlesthereof, it should be understood that the invention may be otherwiseembodied without departing from such principles.

6 What is claimed is: 1. In a paper making apparatus of the type inwhicha Web of relatively wet stock supported on a wire is. carried inoperative relation over the perforated surface of apump operated suctionbox to extract water from the .web passing thereover, the combination.therewith comprising means for discharging such steam into contact onlywith that portion of the pulp web passing over said perforated surfacewhereby the steam, as it is drawn through the pulp web and theperforated surface and into the suction box by the vacuum maintainedtherein by the pump, intermixes and is entrained with the water of saidweb and becomes condensed through heat 'exchange therewith, therebydeveloping in the suction box a vacuum additive to that of the pump, andaccelerating the extraction of water from the pulp web, and meansindependent of said steam discharging means operable to discharge aspray of relatively cold water from within the suction box into the pathof the mixed and entrained steam to amplify the steam condensing actionand increase the effective vacuum in the suction box.

2. In a paper making apparatus of the typeinwhich a Web of relativelywet stock supported on a wire is carried in operative relation over theperforated surface of a pump operated suction box to extract water fromthe web passing thereover, the combination therewith comprising asteamdischargepipe extending axially and above said perforated surface,and axially disposed deflectors extending from both sides of said pipetoward the web, said steam discharge pipe having a series of angularperforation arranged to discharge steam against the deflectors fordeflection thereof only on that portion of the pulp web passing over theaforesaidperforated surface, whereby the steam, as it is drawn throughthe pulp web and the perforated surface and into the suction box by thevacuum maintained therein by the pump, intermixes and is entrained withthe water of said web and becomes condensed through heat exchangetherewith, thereby developing in the suction box a vacuum additive tothatof the pump and accelerating the extraction of water from the pulpweb.

3. In a paper making apparatus of the type in which a Web of relativelywetstock supported one wire is carried in operative relation over theperforated surface of a pump operated suction box to extract water fromthe web passing thereover, the combination therewith comprising a steamdischarge pipe extending axially and above said perforated surface,axially disposed deflectors extending from bothsides of said pipe towardthe web, said steam discharge pipe having a series of angularperforations arranged to discharge steam against the deflectors fordeflection thereof only on that portion of the pulp web passing over theaforesaid perforated surface, whereby the steam, as it is drawn throughthe pulp web and the perforated surface and into the suction box by thevacuum maintained therein by the pump, intermixes and is entrained withthe water of said web and becomes cendensed through heat exchangetherewith, thereby developing in the suction box a vacuum additive tothat of the pump and accelerating the extraction of water from the pulpweb, and means operable to discharge of spray of relatively cold waterinto the suction box to amplify the steam condensing action and increasethe effective vacuum in the suction box.

4. In a paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated surface of a pump operated suction box to extract water fromthe web passing thereover, the combination therewith comprising a steamdischarge pipe extending axially and above said perforated surface, andaxially disposed deflectors extending from both sides of said pipetoward the: web and supertending a surface area of less width than thatsubtended by the suction box to provide air seals between the edges ofthe deflectors and the web, said steam discharge pipe having a series ofangular perforations arranged to discharge steam against the deflectorsfor deflection thereof only onthat portion of the pulp web passing overthe perforated surface, whereby the steam, as it is drawn through thepulp web and the perforated surface and into the suction box by thevacuum maintained therein by the pump, intermixes and is entrained withthe water of said web and becomes condensed through heat exchangetherewith, thereby developing in the suction box a vacuum additive tothat of the pump and accelerating the extraction of water from the pulpweb.

5. In a paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated surface of a pump operated suction box to extract water fromthe web passing thereover, the combination therewith comprising a steamdischarge pipe extending axially and above said perforated surface,axially disposed deflectors extending from both sides of said pipetoward the web and supertending a surface area of less width than thatsubtended by the suction box to provide air seals between the edges ofthe deflectors and the web, said steam discharge pipe having a series ofangular perforations arranged to discharge steam against the deflectorsfor deflection thereof only on that portion of the pulp web passing overthe perforated surface, whereby the steam, as it is drawn through thepulp web and the perforated surface and into the suction box by thevacuum maintained therein by the pump, intermixes and is entrained withthe water of said web and becomes condensed through heat exchangetherewith, thereby developing in the suction box a vacuum additive tothat of the pump and accelerating the extraction of Water from the pulpweb, and means operable to discharge a spray of relatively cold Waterinto the suction box to amplify thesteam condensing action and increasethe effective vacuum in the suction box.

6. In paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drurn having a pump operated suctionbox subtending an arcuate area of the inner surface of the shell toextract water from the Web passing over such arcuate area, thecombination therewith comprising means for discharging such steam intocontact only with that portion of the pulp web passing over said arcuatearea, whereby the steam, as it is drawn through the pulp web and shellperforations by the vacuum in the suction box maintained by the pump,intermixes and is entrained with the water of said web and becomescondensed through heat exchange therewith, thereby developing in thesuction box a vacuum 1,

additive to that of the pump and accelerating the extraction of waterfrom the pulp web, and means independent of said steam discharging meansoperable to discharge a spray of relatively cold water from within thesuction box into the path of the mixed and entrained steam to amplifythe steam condensing action and increase the effective vacuum in thesuction box.

7. In paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam discharge pipe extending axially of thearcuate area of said drum and having perforations arranged to dischargesteam only along that portion of the web passing over such arcuate area,whereby the steam, as it is drawn through the pulp web and shellperforations by the vacuum in the suction box maintained by the pump,intermixes and is entrained with the water of said web and becomescondensed through heat exchange therewith, thereby developing in thesuction box a vacuum additive to that of the pump and accelerating theextraction of water from the pulp web, and means independent of saidsteam discharging means (.3 operable to discharge a spray of relativelycold Water from within the suction box into the path of the mixed andentrained steam to amplify the steam condensing action and increase theeffective vacuum in the suction box.

8. in paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam discharge pipe extending axially of saidarcuate area exteriorly of the drum and axially disposed deflectorsextending from both sides of said pipe toward the web, said steamdischarge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the arcuate area, whereby thesteam, as it is drawn through the pulp web and shell perforations by thevacuum in the suction box maintained by the pump, intermixes and isentrained with the water of said web and becomes condensed through heatexchange therewith, thereby developing in the suction box a vacuumadditive to that of the pump and accelerating the extraction of Waterfrom the pulp web.

9. In paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam discharge pipe extending axially of saidarcuate area exteriorly of the drum and axially disposed deflectorsextending from both sides of said pipe toward the web, said steamdischarge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the arcuate area, whereby thesteam, as it is drawn through the pulp web and shell perforations by thevacuum in the suction box maintained by the pump, intermixes and isentrained with the water of said web and becomes condensed through heatexchange therewith, thereby developing in the suction box a vacuumadditive to that of the pump and accelerating the extraction of waterfrom the pulp web, and means operable to discharge a spray of relativelycold water into the suction box to amplify the steam condensing actionand increase the effective vacuum in the suction box.

10. In paper making apparatus of the type in which a Web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam discharge pipe extending axially of saidarcuate area exteriorly of the drum and axially disposed deflectorsextending from both sides of said pipe toward the web and supertendingan arcuate area of less width than that subtended by the suction box, toprovide air seals between the edges of the deflectors and the web, saidsteam discharge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the arcuate area, whereby thesteam, as it is drawn through the pulp web and shell perforations by thevacuum in the suction box maintained by the pump, intermixes and isentrained with the water of said web and becomes condensed through heatexchange therewith, thereby developing in the suction box a vacuumadditive to that of the pump and accelerating the extraction of waterfrom the pulp web.

11. In paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam discharge pipe extending axially of saidarcuate area exteriorly of the drum and axially disposed deflectorsextending from both sides of said pipe toward the web and supertendingan arcuate area of less width than that subtended by the suction box, toprovide air seals between the edges of the deflectors and the web saidsteam discharge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the arcuate area, whereby thesteam, as it is drawn through the pulp web and shell perforations by thevacuum in the suction box maintained by the pump, intermixes and isentrained with the water of said web and becomes condensed through heatexchange therewith, thereby developing in the suction box a vacuumadditive to that of the pump and accelerating the extraction of waterfrom the pulp web, and means operable to discharge a spray of relativelycold water into the suction box to amplify the steam condensing actionand increase the effective vacuum in the suction box.

12. In paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated shell of an extractor drum having a pump operated suction boxsubtending an arcuate area of the inner surface of the shell to extractwater from the web passing over such arcuate area, the combinationtherewith comprising a steam dis charge pipe extending axially of saidarcuate area exteriorly of the drum and axially disposed deflectorsextending from both sides of said pipe toward the web and supertendingan arcuate area of less width than that subtended by the suction box, toprovide air seals between the edges of the deflectors and the web, saidsteam discharge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the arcuate area, whereby thesteam, as it is drawn through the pulp web and shell perforations by thevacuum in the suction box maintained by the pump, intermixes and isentrained with the Water of said web and becomes condensed through heatexchange therewith, thereby developing in the suction box a vacuumadditive to that of the pump and accelerating the extraction of waterfrom the pulp web, and means operable to discharge a spray of relativelycold water into the suction box to amplify the steam condensing actionand increase the eflective vacuum in the suction box, said spraydischarge means comprising a pipe extending axially through said suctionbox and having a series of spaced angularly directed perforations fordischarging the spray upwardly into the path of movement of the steamand water being drawn into the suction box.

13. In a paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated planar surface of a pump operated suction box to extractwater from the web passing thereover, the combination therewithcomprising a steam discharge pipe extending axially and above saidplanar perforated surface, and axially disposed deflectors extendingfrom both sides of said pipe toward the web and supertending a surfacearea of less width than that subtended by the suction box to provide airseals between the edges of the deflectors and the web, said steamdischarge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the aforesaid perforatedsurface, whereby the steam, as it is drawn through the pulp web and theaforesaid perforated surface and into the suction box by the vacuummaintained therein by the pump, inter mixes and is entrained with thewater of said web and becomes condensed through heat exchange therewith,thereby developing in the suction box a vacuum additive to that of thepump and accelerating the extraction of water from the pulp web.

14. In a paper making apparatus of the type in which a web of relativelywet stock supported on a wire is carried in operative relation over theperforated planar surface of a pump operated suction box to extractwater from the web passing thereover, the combination therewithcomprising a steam discharge pipe extending axially and above saidplanar perforated surface, and axially disposed deflectors extendingfrom both sides of said pipe toward the web and supertending a surfacearea of less width than that subtended by the suction box to provide airseals between the edges of the deflectors and the web, said steamdischarge pipe having a series of angular perforations arranged todischarge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the aforesaid perforatedsurface, whereby the steam, as it is drawn through the pulp web and theaforesaid perforated surface and into the suction box by the vacuummaintained therein by the pump, intermixes and is entrained with thewater of said web and becomes condensed through heat exchange therewith,thereby developing in the suction box a vacuum additive to that of thepump and accelerating the extraction of water from the pulp web, andmeans operable to discharge a spray of relatively cold water into thesuction box to amplify the steam condensing action and increase theeffective vacuum in the suction box.

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